Release-valve for air-brakes



(No Model.) 2 SheetsSheet 1.

v G. A. BOYDEN.

RELEASE VALVE FOR AIR BRAKES.-

INVENTOR I Patented June 4 F H H H! l I lllilli'j llilii. 1}

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(No. Model.) 2 Sheets-Sheet 2.

G. A. BOYDEN. RELEASE VALVE FOR AIR BRAKES. No. 404,768. Patented June l, 1889,

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UNITED STATES PATE T OFFICE.

GEORGE A. BOYDEN, OF BALTIMORE, MARYLAND, ASSIGNOR TO THE BOYDEN POWVER BRAKE COMPANY OF BALTIMORE CITY, OF MARYLAND.

RELEASE-VALVE FOR AIR-BRAKES.

SPECIFICATION forming part of Letters Patent No. 404,768, dated June 4, 1889.

Serial No. 246,950- (No model.)

To all whom it may concern:

Be it known that I, GEORGE A. BOYDEN, a citizen of the United States, residing at Baltimore, in the State of Maryland, have invented certain new and useful Improvements in Release-Valves for Air-Brakes, of which the following is a specification. a

My invention relates to improvements in the construction and operation of relief-valves for quickly releasing the air-pressure in the expansible chambers and train-pipe employed to operate the brake mechanism on railroadears.

My release-valve is so constructed and applied that when the air-pressure is released in the first section of the train-pipe by the engineer the succeeding sections, which are under each car, will bythis device be automatically and instantly relieved of air-pressure, which will cause the brakes of the train to be quickly applied.

The invention is illustrated in the accompanyin g drawings, in which- I Figure 1 is an end view in full of the reliefvalve. Fig. 2 is a longitudinal section through the relief-valve, and shows the position of the parts when the air-pressure is on and from the direction indicated by the darts. Fig. 3 is a detailed View of the large valve, looking to the left. Fig. 4 is a section through the yoke on line 4 4, showing intermediate valve, looking to the left. Fig. 5 is aview of the intermediate valve. Fig. 6 is a plan of a car and showing the train-pipe and the manner of connecting and applying the release-valves. Fig. 7 is an elevation in section of the two release-valves as they are applied to the trainpipe.

The letter C designates a casting of suitable metal, which comprises thebody or casing of the relief-valve, and in which is formed the cylinder D, the passages F G, for air, and the bore I, for a cock-plug I. The cylinder D is provided at one end with a port a, which may communicate with either one of the ways a or G of the cock-plug I, in a manner hereinafter described. At this end also is a valve-seat b for the valve which closes the port a. At the other end the cylinder is closed by a plug H, which is provided with an air-escape port 0. At this end is a side port d, which opens into the air-passage G, wherein the section of train-pipe B which is under the car is screwed to the thread 6. The air-pas sage F also has a thread 6, with whicha pipe or hose g is attached for connection with the section of train-pipe on another car. Both passages F G lead to the cock-plug bore I. The cock-plug I has two ways a G, either one of which may be used. hen the plug is in one position, the way a will establish communication for air from the passage F through'the port a into the cylinderD where the relief-valve is located, and from the side port (1 into the passage G. This position is shown in Fig. 2, and also in the valve at the right of Fig. 7. Then the cock-plug I is in the other position, (see the valve at the left of Fig. 7,) the way G will establish communi- 1 cation for air from the one passage G directly into the other passage F, and thus avoid or pass around the relief-valve;

The cock-plug I has a handle or lever f, which is se cured thereto in such position that when it is desired that the relief-valve shall be operative the said handle must point toward the direction wherefrom the air-pressure comes, as shown in Fig. 2; and, on the other hand, when it is desired to cut out the relief-valve, or, in other words, have the air pass around it, the handle f must point in the opposite direction-that is, toward the end plug H. This relief-valve and the best man- 1] er of operating it contemplates the employment of two valves in the train-pipe on each car, one to be located at each end of the car E or at each side of the expansible chamber A, as shown in Fig. 6. The relative position of the two valves on the same car is reversed. This is shown in both Figs. 6 and 7, where, it will be seen, the end plugs II of the two valves point toward each other. By this arrangement and combination all liability of confusion or inisplacing the handles or levers f will be avoided, as, in order to have the valves 5 operate properly, the rule will be for all the handles to point toward the direction (the 10- comotive usually) wherefrom the air-pressure comes. From the fact that the two valves on each car are exactly alike but have reversed 10o position with respect to each other it follows that by pointing the handles f of both valves in the same direction one relief-valve will be operative while the other one will be cut out.

Two pistons J J fit and are movable in the cylinder D. They are connected together by a yoke K, and they cannot move separately. The piston J, next to the seat 1), has a central opening 72, (see Figs. 23 and 7,) and on its front or outer face around said openin has a gasket b, secured by screws 1)". \Vhen the pistons move toward the said seat I), the gasket comes in contacttherewith. An intermediate valve IL is located between the two pistons and the two arms of the yoke K. This valve Ii seats itself against the back or inner face of the first piston J and serves to guard the central opening h therein. Thus the first piston J and the intermediate valve L act as a valve for the port a, which communicates with the two ways in the cock-plug I. The intermediate valve L is provided with a stem '1', which fits and moves in a guide on the yoke. The second piston J is solid or with out opening, and on its outer face has a gasket 7;, which serves as a valve for the escapeport 0 in the end plug II. The escape-port c is the communication between the train-pipe B and the atmosphere, and is controlled by valve-gasket]; and the movement of the said two pistons.

The manner in which this relief-valve operates is as follows: As represented in liigs. (3 and 7, two relief-valves are employed. on one car, one valve being placed at each end of the train-pipe I with which each car is provided, and which forms one complete section, as previously described. The handlesfhavin been turned toward the locomotive the valve to the right of Fig. 7 becomes the operative one, while the valve to the left is cut out. Air being admitted to the train-pipe by the engineer will pass into one end of the cylinder D of the operative val ve through the port (1 The air-pressure will. move the pistons J J, and the port 0, which is open to the air, will be closed by the valve-gasket It. At the same time the intermediate valve IL will be opened and communication will be established through the side port (I and passage G into the train-pipe 13 on the car. The air will pass from this section of train-pipe into the next section, which is on the adjoining car, through the valve which is cut out, the course therein of the air being through the air-passage G, the way pl in the cock-plug I, and air-passage F, thus avoiding the relief-valve pistons, the internal air-pressure keeping the second piston J of this cut-out valve pressed against the cscapeqiort e, thereby making this valve air tight.

\Vhen it is desired to apply the brakes the first section of the train-pipe will be released of its air-pressure in the usual manner by the engineer. Such release will be immediately made manifest in the next section by the movement of the pistons J J in the operative valve in consequence of the lessened pressure on the side of the said pistons next to the locomotive. The movement of the pistons will open the escape-port e, and the airin this section of the train-pipe will escape by way of the side port (I and port (1, the release of pressure in this section being made manifest to the succeeding section of the train-pipe through the coek-plug I of the cut-out valve in the manner heretofore described, and the release-valves undereach car will be caused to instantly succeed each other in action in the discharge of airpressure in their respective sections of train-pipe. Thus when the air-pressure is released in the first section of train-pipe by the engineer such release will be made manifest throughout the train by the automatic discharge of air in each section of train-pipe.

The cut-out valve becomes the operative one when the other end of the car is turned toward the locomotive, both handles being in this case moved through an arc of one hundred. and eighty degrees, which, in the manner heretofore described, places the two ways in the cock-plug in proper position.

The expansible chamber A herein referred to is meantto include such as employ a flexible dia1 )hragm, cylinders with pistons, or any other known form.

Ilavingdescribed myinvei'itiomlclaim and desire to secure by Letters Patent of the United State.

1. In a fluid car-brake, the combination of the release-valve having passages F G for connection with the train-pipe, and a cock I, controlling said passages, whereby to make the valve operative or inoperative.

2. In a fluid car-ln'ake, the combination of the train-pi ie 1:3 on the car, an expansible chamber, two air-release valves, one on each side of the expansible chamber, and the cocks 1, arranged to make either valve operative or inoperative.

In a fluid car-brake, the combination of the train-pipe having its terminals at opposite ends of the car, two air-release valves on the train-pipe between the said terminals, and the cooks, for the purpose set forth.

In testimony whereof I affix my signature in the presence of two witnesses.

GE()RG'IC A. BO'YDEN.

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